Frictional locking-hinge.



No. 757,492. PATENTED APR. 19, 1904.

' P. G. PALMER.

FRIGTIONAL'LOGKING HINGE.

APPLICATION IILED APR. 30, 1903.

N0 MODEL.

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Patented April 19, 1904.

PATENT OFFICE.

PHILIP C. PALMER, OF KANSAS CITY, MISSOURI.

FRICYTIONAL LOCKING-HINGE.

SPECIFICATION forming part of Letters Patent No. 757,492, dated April 19, 1904,

Ap nmim filed April 20, 1903.

1'0 all whom itrnctj concern; Be it known that I, PHILIP OOFFMAN PAL- MER, a citizen of the United States, residing the hinge.

at Kansas City, in the county of. Jackson and State of Missouri, have invented certain new and useful Improvementsin Frictional Locking-Hinges, of which the following is a specification. V

My invention relates to improvements in frictional locking-hinges and is adapted for use in connection with physicians operatingchairs, hospital operating-tables, adjustable invalid-beds, dentist, barber, and railway-car chairs, door-hinges, window-blind hinges, transom-hinges, &c.; and my object is to produce a hinge whereby the connecting parts may be readily adjusted to any desired position and reliably locked therein until released by the operator. 1

In the accompanying drawings, Figure 1 represents my improved frictional lockinghinge applied to a physicians operating-chair. Fig. 2 is an enlarged detail side elevation of Fig. 3 is a front elevation of the same.

For convenience in describing and illustrating my invention I have shown it applied to a physicians operating-chair consisting of a pedestal 1, mounted upon ball-bearing casters 2, a ball-and-socket connection 3, interposed between the pedestal and the seat 4, an adjust' able footboard and back 5 and 6, and arms 7. In the present instanceI have shown the footboard and the back connected to the seat by my improved frictional locking-hinges, each of which consists of a rigid inner ring 8, cast integral with an arm 9, that is secured to the side of the chair-back and provided with an integral flange 10, extending at right angles thereto for the purpose of engaging the rear surface of the back in orderto provide-a reliable support for the latter. The periphery of ring 8 is preferably ground smooth in order that its entire surface may be reliably gripped by the inner frictional surface of a flexible split ring 11, provided at its severed portion with oppositely-disposed integral jaws 12 13, the former of which is cast integral with an arm 14, adapted to be secured to the side of the seat and provided with an upper integral Serial No. 153,451. (No model.)

flange 15, extending-at right angles thereto for the purpose of engaging the upper portion of the seat, and thus afford a more reliable connection between the latter and said arm. Jaw 13 is formed integral with the free portion of the split ring and provided at its rear side with'a wedge 16, havinga right-angular lower portion 17', which is pierced for the reception of an adjusting-screw 18, the upper threaded end of which engages an internallythreaded bore 19 in jaw 13. The lower end of the adjusting-screw is provided with a grooved head 20 for engagement with a screw driver, and said screw is also provided with a lock-nut 21, adapted to engage the end of jaw 13 in order to lock the adjusting-screw from accidental movement. When in its normal position, the flexible split ring 11 embraces ring 8 so loosely that the back of the chair may be readily adjusted to any position; but when it is desired to lock it at any particular angle the frictional surface of the split ring is drawn tightly in contact with the periphery of ring 8 by means of a lever 22 underlying ring 11 and pivoted to arm 14: at 23 and provided at its pivoted end with a cam-face 24, which presses wedge 16 and jaw 13 toward jaw 12 when the handle of said lever is elevated to the position shown in Fig. 2. Should the wedge unintentionally be adjusted too far in between the cam-face and jaw 13, the latter is protected from such undue movement as would be liable to fracture it by a set-screw 25, projecting from the adjacent side of jaw 12, it of course being understood that said set-screw is not intended to limit the gripping action of the split ring, but is simply intended to prevent such undue movement of jaw 13 as torender it liable to fracture after said gripping action has taken place. All perceptible wear of the frictional surfaces of the rings and the cam-face is readily taken up by proper manipulation of wedge 16, so that the requisite movement may at all times be imparted to the split ring in order to make it look ring 8 from further movement.

From the above description it is apparent thatI have produced a frictional locking-hinge preferred embodiment of the same it of course is understood that it is susceptible of modification in various particulars without departing from the principle and scope of the following claims.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is

1. In a frictional locking-hinge, a rigid member, a flexible member encircling the same and provided with integral jaws, means for moving said jaws toward each other, and adjustable means for limiting said movement.

2. In africtional locking-hinge, an arm provided with a rigid inner ring, another arm provided with a split ring loosely embracing the inner ring, jaws formed integral with the adjacent ends of the split ring, a wedge adjustably secured to one of said jaws, and a lever fulcrumed on one of the arms and provided witha cam-face adapted to press against said wedge in order to cause the split ring to tightly engage the inner ring.

3. In a frictional locking-hinge, an arm, a ring formed integral therewith, another arm, a split ring secured thereto and loosely embracing said ring, jaws formed integral with the adjacent ends of the split ring, an adjusting-screw engaging one of said jaws, a wedge suitably secured to said adjusting-screw, and a lever fulcrumed on one of the arms and having a cam-face adapted to impart movement to the wedge and jaw.

4:. In a frictional locking-hinge, an arm, a ring formed integral therewith, another arm, a split ring secured thereto and loosely embracing the first-mentioned ring, jaws formed integral with the adjacent ends of the split ring, a lever fulcrumed on one of the arms and provided with a cam-face adapted to impart movement to one of said jaws, and aset-' jaws, a wedge adjustably secured to the opposite jaw, and a lever fulcrumed on one of the arms and provided with a cam-face adapted to press the wedge-containing jaw toward the projecting end of the set-screw.

In testimony whereof I aflix my signature in the presence of two witnesses.

PHILIP C. PALMER.

Witnesses:

F. G. FISCHER, T. A. HIGKEY. 

